‘Smart Dust’ for Planetary Exploration

byPaul GilsteronApril 18, 2007

Bringing computer networking to space exploration is a major step forward. It allows us to go beyond the old model of pointing radio dishes at a specific spacecraft and downloading information — a time-consuming process as we move from one spacecraft to another — to communicate instead with a single hub vehicle that could be processing data from a cluster of sources. That maximizes precious communications resources here on Earth and allows us to connect planetary rovers, for example, with base stations, orbiting spacecraft and other nearby vehicles.

We’ve talked about interplanetary networking before in terms of the InterPlanetary Internet Project (IPN), a key player in which is Internet legend Vinton Cerf. But extend the idea further, as John Barker (University of Glasgow) is doing today at the Royal Astronomical Society’s national meeting in Lancashire (UK). What Barker has in mind is using ‘smart dust’ — tiny computer chips surrounded by a polymer sheath — to form intelligent swarms for research on a planetary surface.

Here’s how Barker explains the idea:

“We envisage that most of the particles can only talk to their nearest neighbours but a few can communicate at much longer distances. In our simulations we’ve shown that a swarm of 50 smart dust particles can organise themselves into a star formation, even in turbulent wind. The ability to fly in formation means that the smart dust could form a phased array. It would then be possible to process information between the distributed computer chips and collectively beam a signal back to an orbiting spacecraft.”

How to control the motion of smart dust in such an environment? The surface of the polymer sheath surrounding the chip can be smoothed or wrinkled depending on the application of a small voltage. Switching between rough and smooth modes adjusts the drag on the particle, allowing it to rise or settle toward the surface. Controlling these modes allows the particles to move toward their target despite ambient weather conditions.

Image: The University of Glasgow team has studied the collective movement of motes towards a target located in a portion of the Martian surface that extends over a range of several kilometers. A smart dust mote has approximately the density and volume of a coarse grain of sand. It follows that the uncontrolled motion of smart dust is determined by the same Aeolian processes of saltation, settling and surface creep that govern the movement of sand in desert regions. Adjusting the surface of smart dust particles provides one way to control their motion. Credit: John Barker/University of Glasgow.

Barker notes a key problem with current technology. Today’s chemical sensors are too large for particles the size of sand-grains that might be carried by the Martian wind for deployment. But the denser atmosphere of Venus could carry particles up to a few centimeters in size. In any case, as we move forward not many years, our chip components should reach sizes of a few nanometers across, making them, in Barker’s thinking, more like molecules diffusing through an atmosphere than dust grains.

Nanotechnology will have an extraordinary effect on space exploration, offering in a few short years options that would otherwise have been impossible. The team at Glasgow knows that and is clearly unafraid to think big. Acknowledging that smart dust is years away from deployment on an actual mission, Barker looks well down the road at interstellar implications: “Our first close-up studies of extra-solar planets could come from a smart dust swarm delivered to another solar system by ion-drive.”

Interesting idea… it has obvious science-fiction applications, whether in terms of human characters secretly observing an alien culture or aliens clandestinely watching us. Although I assume that if there were alien smart-dust devices studying our civilization, we could detect their radio transmissions.

But how much information, and of what types, could smart-dust devices collect?

Yes, and I was about to ask readers for suggestions re science fiction treatments of smart dust. Just curious to see how the notion has been handled with regard to space exploration. I think we’re very early in the game to be able to say just what kind of measurements might be gathered with these devices, but it does seem that advancing nano technologies should open a wide range of options.

I would think that the tiny size would tightly constrain the quantity of circuit elements (what it can do) and also the power and wavelength of radio comms.

Might be a less less futuristic to increase the size of the particle, say up to 1 cm to keep it reasonably unremarkable to observers but open up technical options, and make it buoyant (low density).

I remember one book by Greg Bear (“The Forge of God”) where vest numbers of self-replicating and inter-communicating tiny automatons scour the Earth cataloging all flora and fauna. He made them large enough to enable directed mobility rather than just tumbling around in the wind.

Yes, I think so. Anything that helps us reduce payload size helps deep space missions, so getting this work down to the nanotech level does have interstellar implications. Of course, the biggest key to the puzzle is still propulsion, but the less mass we have to push, the better. Tomorrow’s post will look at some of the implications of nanotech for one particular kind of interstellar propulsion system.

I just had an interesting thought. What if you launched, over specified intervals of time, millions of “smart sensors” from near-earth orbit towards nearby planets, or even other star systems, as long chains of communication. (I imagine an eletromagnetic rail-gun-like cannon for launching the sensors – although the devices would have to be shielded from the magnetic part). The sensors would report back to each other successively as they travel and collect data. You would end up with a continuous flow of information coming from the entire chain giving you a “light-speed” real-time report between here and the farthest sensor. I imagine the type of sensor could be varied in the deployment, but all of them would share the ability to maintain network connectivity and report back sensor data.

Is this a concept of interplanetary or interstellar exploration which has been previously discussed?

I do imagine this has some negative aspects (such as cluttering space with objects large enough to cause damage to future manned vehicles if they happened to hit one at high relative speeds – even if they would be few and very far apart on interstellar scales).

A chain of sensors reaching across a vast distance. Interesting idea! Each can be low powered and simply communicate along the chain — it’s sort of like the fire beacons atop mountains that the ancient Greeks used to move news at otherwise unobtainable speeds (and digging around, I just found that Caesar said the Gauls could call their armies up in just three days using their own variant of this). Positioning would be a problem, but I know various particle propulsion concepts deal with this — Gerald Nordley talks about using smart particles that can adjust their position, etc. So it’s hard to say this wouldn’t be possible. I’ll be interested in what readers say here about advantages, disadvantages, etc.

It makes one wonder how much of the dust that permeates
the galaxy is actually natural?

We keep looking for massive starships full of organic crews
with huge fusion drives plowing through interstellar space,
while we pay no attention to that dust flitting about our heads
and laying quietly on our coffee tables.

Yes, and I was about to ask readers for suggestions re science fiction treatments of smart dust. Just curious to see how the notion has been handled with regard to space exploration.

Heh-heh, my cue. The following is kind of close. Synopsis of The Red Moon Mystery, starring Dan Dare, Pilot of the Future, in the comic magazine, serialized 1951-52.

The celestial body in question is discovered in the Asteroid Belt, on a close approach to Mars. It does all the right Velikovskian things: raises tides, causes electrical storms, and somehow caused the destruction of the ancient Martian civilization;shortly it changes course for Earth. In a couple of near-disastrous missions, Dan and Co. find that the planetoid has an intense magnetic field, and a dust-laden atmosphere some tens of miles deep; and finally its secret is revealed.

The Red Moon is home to a species of space beetles. In their ceaseless burrowing, they have thrown up this rotating sphere of dust, which acts as a “dynamo”, generating the magnetic field. (Reasonable: there could be plenty of photoelectric emission, and the moon’s rotation would provide the energy.) The beetles themselves, each a few inches in size, have wings which are magnetic dipoles, north on one side, south on the other, and so can flit around in space in the vicinity of their moon. Once in a while they make a pass by some inhabited world, and strip it of vegetation. Our heroes lure it away from Earth by means of a large lantern radiating the chlorophyll emission spectrum.

A nifty piece of scientific thinking, all told, and it has set me thinking sometimes about the possibilities of smart ferromagnetic dust, or artificial space beetles. Something combining a photovoltaic cell, a solenoid and a gyroscope, able to orient itself in an ambient magnetic field; and collectively able to manipulate the field for electric propulsion (or M2P2), or for clinging on to nickel-iron asteroids. One can vaguely see how flocking algorithms could manage the collective motions, but I haven’t been able to see what swarm configurations would be maintainable.

A case for neural nets, genetic algorithms and someone with a lot of time on their hands.

I have “long” envisioned a scenario where thousands (millions?) of nanoprobes are launched using a laser cannon on the far side of the moon. these are about the size of a grain of sand. they are capable of manufacturing (nanofacturing?) copies of themselves from materials that they encounter at the target. mechanism? beats me.. maybe based on a nano-mass spectrometer?

how long for technology to evolve to a level capable of such devices? i’d give it less than 100 years.

for an odd, rambling story that arrives at a similar idea, see “autofac” by phillip k. dick.

strange consequence occurs though: might such things be considered ‘alive’?

“It makes one wonder how much of the dust that permeates
the galaxy is actually natural?”

Ooooooh, shivers! It makes perfect sense – the more advanced a civilization is, the more likely it is to develop the most efficient and inexpensive ( in terms of energy, being-hours etc) solutions to basic problems. And since efficiency is a universal concept, pretty much everyone will eventually arrive at nano-dust as a means of exploring the universe. Discovering even one grain of artificial nanodust would pretty much resolve the Fermi Paradox once and for all.

Just had another interesting thought -this could be the basis for a science fiction story (or could it be real?). Using nano-technology and the smart-dust approach to exploring planets, why not disguise your planetary exploration in small sensors hidden in meteorites? (Assuming the sensors can survive re-entry.) Imagine if one of our nano-technology experts started analyzing meteorites and discovered such sensors? Meteorites get placed in museums where millions of people walk by – I could just imagine an advanced technological race learning more about our planet, and its people, using this technique!

Frank, it’s a fascinating notion, that’s for sure. When I was researching Centauri Dreams (the book) I talked to one scientist with a great interest in nanotechnology who speculated on sensor grids that could span the planet and be all but undetectable by us. Nanotech in smart dust –even in meteorites — isn’t such a far reach from that. Of course, what gets me thinking even more is that we can envision the implications of at least some nanotech. But could we begin to envision what a culture a million years older than our own might be able to do?

Insects are the ultimate “nanobots”. They self-replicate, are ubiquitous in all ecological niches, adapt quicky to environmental changes, are resistant to high levels of radiation, are relatively covert, and can basically power themselves off dust. They could easily be reprogrammed at the genetic level by an advanced species to be the perfect information gatherers. If I wanted to exlore a planet, I’d do some fiddling with cockroaches, mites or dragonflies, easily among the hardiest lifeforms on earth.

Most robots have legs, wheels, or tank-like treads.
But Virgina Tech roboticist Dennis Hong is building one
that uses “whole-skin locomotion” to move like an
amoeba, enabling it to squeeze more easily into the
some of the tight other-worldly spaces where
extraterrestrial life might be hiding.

New Artificial Organism with Advanced Group Intelligence:
A Swarm of 10,000 Miniature Robots

Remember Michael Crichton’s science-fiction novel, “Prey”?
Well, researchers at the University of York are investigating
large swarms of up to 10,000 miniature robots which can work
together to form a single, artificial life form. The multi-robot
approach to artificial intelligence is a relatively new one, and
has developed from studies of the swarm behavior of social
insects such as ants.

Swarm robotics is a field of study based on the supposition that
simple, individual robots can interact and collaborate to form a
single artificial organism with more advanced group intelligence.

As a part of an international collaboration dubbed the “Symbiotic
Evolutionary Robot Organisms” project, or “Symbrion” for short,
researchers are developing an artificial immune system which
can protect both the individual robots that form part of a swarm,
as well as the larger, collective organism.

The aim of the project is to develop the novel principles behind
the ways in which robots can evolve and work together in large
‘swarms’ so that – eventually – these can be applied to real-world applications. The swarms of robots are capable of forming
themselves into a ‘symbiotic artificial organism’ and collectively
interacting with the physical world using sensors.

how about using smart-dust instead of rfid-chips? then everything we do can be traced and tracked? like rats. that would be cool.
how about dropping it out of tankers and planes over areas and let it land everywhere and be inhaled into bodies? through chemtrails perhaps. yeah, that would be “cool”. fun for the whole family. we can become one giant borg under the United Nations and the New World Order. Pretty cool. Bring it ON !!!

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For the last twelve years, this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image: Marco Lorenzi).

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